Research Of AC Variable Frequency Regulating Source System Based On Single Cycle Control

With the development of power electronics technology,AC variable frequency regulating source has been rapidly developed,widely used in various national fields.However,some traditional power supplies have the disadvantages of high harmonic factor,small range of voltage and frequency regulation modulation,low power factor,and so on,which can not meet the needs of the development of science and technology.Therefore,it is very important to study power supplies with high efficiency and little pollution.Power electronic converter control technology is the core technology of converter.As a result,designing of a good control method is essential for source system.This paper studies the feasibility of AC variable frequency regulating source system under single cycle control technology,and applies single cycle control technology to AC variable frequency regulating source.First of all,the advantages and disadvantages of several basic variable frequency regulating circuits were introduced.The main circuit structure of AC-DC-AC was selected,the device parameters of which were determined,and the switch snubber circuit was designed.Secondly,three control methods were applied to the inverter circuit to analyze the working principle and respective performance of each single-cycle controller.The constant frequency single-pole single-cycle controller was determined by comparing the advantages and disadvantages of each controller.Thirdly,the post-stage voltage and current double closed-loop control was introduced,which was combined with the previous single-cycle control to make up for the shortcoming of slow dynamic response of load disturbance in control system.Finally,the power simulation models under three single-cycle control modes were built by using multism12 software.The simulation model of voltage-current double closed-loop control was built by using Matlab/Similink software.The test platform of variable frequency regulating source system with dsPIC high performance digital processor and single cycle controller as the core was set up,including IGBT drive circuit,voltage-current sampling circuit and communication circuit.The feasibility of applying single-cycle control technology to AC variable frequency regulating sourcewas verified from simulation and experiment aspects.